The RANDOM() functions return a random real number.
RANDOM() returns a random real number from 0 to, but not including, 1.
RANDOM(N) returns a random real number from 0 to, but not including, N.
RANDOM(A,B) returns (v9.0+) a random real number from A to, but not including, B.
In the two parameter version, A must not equal B, and if B is less than A, they are implicitly swapped.